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Uncommon variable star 25 EP

13 Com

RA 186.0772° · Dec 26.0986° · star

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Score breakdown

· 6 badges
25 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Variable star +5
  • White A-type star +5
  • A named variable star +3
  • Main-sequence star +2
  • Barely variable (under 0.05 mag) +2
Total score 25

9 more points to reach Rare.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • White A-type star · +5
  • Main-sequence star · +2
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads A3V — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 5.2 you can see it with your own eyes from a dark site, over in Coma Berenices.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

absmag
0.625
bv
0.082
constellation
Com
dist ly
264.5223
luminosity
48.9779
mag
5.17
name
13 Com
spect
A3V
var amplitude
0.01
var designation
GN
var max
5.165
var min
5.175

About 13 Com

13 Com is an uncommon variable star. It lies about 264.5 light-years from Earth, sits in the constellation Com, shines at apparent magnitude 5.17 and has spectral type A3V.

Its spectrum reads A3V — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for 13 Com in the constellation Com. At apparent magnitude 5.17, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 13 Com is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why 13 Com is an uncommon variable star

13 Com scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Naked-eye visible, White A-type star, Main-sequence star, Barely variable (under 0.05 mag) and A named variable star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.